With the development of society, and the increase of labor cost, negative influence of traditional construction model shows all the time, that is, high-altitude working has much potential risk and long construction period, whose construction quality is very hard to be guaranteed and project cost stays at a high level.
Therefore construction method of lifting integrally transforms high-altitude working into ground operation, which greatly reduces potential safety hazard, improves working environment, ensures construction quality, and realizes prefabrication and mechanization of structure installation. Also it enormously betters construction efficiency, construction quality and security of construction procedure of this kind of structure construction. It is especially important and meaningful to current structure construction under circumstance of raising labor cost and tight schedule. It has positive significance to change present construction production from labor-intensive, extensive and backward construction mode into technology-intensive, intensification and advanced construction mode.
However, existing integrally lifting construction methods are mostly performed in good condition of lifting point layout and construction environment. There is no corresponding integrally lifting construction method for installation in other conditions where the obstacles in vertical direction exists or initial lifting position and emplacement position of the structure have different horizontal projections. In this case an assembly in bulk in high altitude is often adopted, but such way has following disadvantages:                (1) Large quantity of high-altitude working, high safety hazard, and difficulty to carry out the safety protection;        (2) Bad environment condition for welding as high-altitude working, which makes it hard to guarantee construction quality;        (3) Large quantity of high-altitude working, bad operational environment condition for welding as high-altitude working, which lead to an inconvenient operation and long construction period on site.        